Address,
     
     One of the many evaluations we perform on boards is Solderability heat 
     test.  This test simulates the affects of repeated soldering and 
     desoldering that could possible occur on a PTH in actual production. 
     
     Test criteria:
     
     a.  Preheat soldering station to  647?F (342?C)
     b.  Fill PTHs with solder, then desolder.  This operation is performed 
         three times to the same PTH.
     c.  After Thermal Shock Testing (another separate test), microsection  
         the PTHs inspect PTHs using 50X~200X.
     
     No cracks in the hole wall or deformation should occur.  The maximum 
     allowance of lifted land from the plane of the base material to the  
     bottem tip of the land shall be =<30?m.
     
     My question is:  Does the 647?F seem abnormal from other vendor specs?
     What station temperture are some of the other assembly shops using?